The present invention relates to a system for correcting a shift of an ignition timing occurring in the ignition device used with internal combustion engines.
In recent years, ignition devices used with motor vehicles have been and are being required to have increased output energy and have both improved accuracy and stability of the ignition timing in view of the purification required for the exhaust gases from motor vehicles. Under these circumstances, ignition devices of the convention contact breaker type are increasingly replaced by those of the fully transistorized type without contact breakers.
In this fully transistorized type of ignition device, the ignition timing signal is provided by a contactless signal generator such as an electromagnetic coil generator, an integrated circuit Hall generator or the like. However, such a generator is disposed within a mating distributor which is, in turn, usually driven by a crank shaft connected to an associated internal combustion engine through a timing belt or the like. Even in fully transistorized ignition devices, therefore, a shift of the ignition timing due to ageing changes in the distributor driving system increases with time. Thus, deviations of the ignition timing signal from its normal position in each cycle of the internal combustion engine due to various causes would increase and become more apparent as time goes on. This has been attributed to, for example, the ageing of a distribution driving mechanism involved. This shift of the ignition timing appears as a shift of the ignition timing developed during the idling of the engine and has greatly affected the output from the engines and the ingredients of the exhaust gases from the engine.
Therefore, the shift of the ignition timing is undesirable in view of measures to purify the exhaust gases from internal combustion engines. Thus, it is desirable to correct a shift of the ignition timing of internal combustion engines by some measure.